In order to meet the requirements for low weight, high mobility and air transportability in conjunction with high protection, military vehicles in the future will be equipped with active protection systems instead of more and more heavy armor.
Such active protection systems are especially designed for the defense of military vehicles against guided missiles, ammunition fired from heavy guns and artillery, and rocket propelled grenades (RPG). Incoming missiles or projectiles will be detected and tracked by a fast-reacting sensor suite having a suitable search and tracking radar, and finally destroyed close to the vehicle by an appropriate counter-fire, such as from a Gatling gun, a fragmentation grenade, or the like. In order to do this, a defense grenade might, for example, be fired from a lightweight launcher that can be aimed extremely quickly in the direction of the incoming projectile. The act of aiming the launcher involves changes in elevation (height axis) and traverse (side axis) to direct the launcher toward the incoming projectile. After being fired, the grenade is exploded in the vicinity of the projectile so that the projectile is neutralized a safe distance away from the vehicle.
For example, RPGs can be fired at military vehicles from short combat distances of less than 100 meters. Hence, active protection systems must have a quick reaction time and the highest dynamics. After target detection, the drive mechanism of the active protection system must be capable of aiming the launcher at the incoming projectile in fractions of a second (i.e., in milliseconds).
In order to facilitate this, the mass and inertia of the movable portion of the launcher must be minimized, and the power available to move the launcher from an initial position to an aimed position must be maximized.
The typical configuration of the aiming drive of the launcher of an active self-protection system includes a drive for each of two orthogonal or mutually-perpendicular intersecting axes (elevation and azimuth). The motor for moving the launcher about the traverse axis is usually installed in the fixed lower mount of the launcher, and rotates the movable upper mount of the launcher either directly (direct drive) or indirectly through a gear. However, the motor for moving the launcher about the elevation axis is commonly installed in the rotating upper mount, and moves the launcher tubes either directly (direct drive) or indirectly through a gear. In this configuration, the elevation motor moves with the movable upper mount, and therefore increases the weight and inertia of the movable upper mount about the transverse axis.
One prior art aiming drive is disclosed in EP 1 096 218 B1. In this construction, a launching container is pivotally held on a pivot support that is rotatable around a horizontal axis. A sub-mount arranged below the pivot support accommodates two azimuth actuators and one elevation actuator. The output pinions of the azimuth actuator mesh with a toothed carrier ring at the pivot support, while the elevation actuator acts by means of a support rod and a spindle drive directly on the launching container. Through this, all motors are mounted on the fixed lower mount so that the mass and inertia of the movable upper mount are minimized, and the power available to move the launcher is maximized. However, in such an arrangement, the two axes are coupled such that movement in the traverse direction also creates a disturbance of the launcher's elevation, which has to be compensated for by a further operation of the elevation motor. Furthermore, the range of movement in aiming the launcher is significantly restricted. For example, aiming directly “over head” is not possible.
A follow-up control for an aiming drive is described in FR 982 021 A.
A lateral aiming drive for a combat vehicle with a turret is known from DE 3 736 262 A1.
Accordingly, it would be highly desirable to provide an improved drive mechanism that is adapted to be mounted on a suitable support (e.g., either stationary or vehicular) for controllably moving a first output shaft (e.g., on which a launcher is mounted) about either or both of two orthogonal axes.